A multidisciplinary molecular virology and immunology program will develop and test DNA and protein immunogens for immunodeficiency virus vaccines. Vaccine trials will be run at the Yerkes Primate Research Center using rhesus macaques and graded SHIV-89.6 challenges. In Project 1, Dr. Harriet Robinson will develop DNA immunogens and evaluate humoral responses. Vaccine DNAs will be designed to express non-infectious SHIV-89.6 particles (VLP) and test new concepts for improved humoral responses. In a sub-contract to this project, Dr. Stephen Johnston of the Southwestern Medical Center, University of Texas, will provide a ubiquitinated SHIV- 89.6 library for evaluating the library approach to improve vaccine efficacy. In Project 2, Dr. Richard Compans of the Emory School of Medicine will develop SHIV-89.6 VLPs as well as 89.6 fusion proteins for testing new concepts for raising long-lasting neutralizing antibody. In Project 3, Dr. John Altman of the Emory Vaccine Center will work with Drs. Brian Barber and Kelly MacDonald of the University of Toronto to type and assign macaques to MHC-matched trial groups, to identify MHC I motifs and to construct MHC tetramers for following T-cell receptor specific responses. In Project 4, Dr. Francois Villinger of the Emory Cancer Center and Dr. Janet McNicholl of the Centers for Disease Control and Prevention will use novel as well as more conventional assays for scoring the CD4 and CD8 T-cell responses raised by the different vaccine protocols. Drs. Harold McClure and Shawn O'Neil of the Yerkes Primate Research Center will provide a primate core and assays for quantitative virus load. Dr. Harriet Robinson will provide administrative support. The first vaccine trial in macaques will use a SHIV-89.6 VLP DNA prime and protein boost in groups comparing (i) i.m. and gene gun inoculations for immunogenicity and protective efficacy, (ii) the potential for co-inoculated genetic adjuvants (GM-CSF plus IL-12 or IL-18) to improve immunogenicity and protection, and (iii) the ability of a ubiquitinated SHIV-89.6 library to improve protection. The second vaccine trial will build on parameters identified as promising in the first trial, and test new concepts developed in Projects 1 and 2.